Supercritical extraction from vinification residues: fatty acids, α-tocopherol, and phenolic compounds in the oil seeds from different varieties of grape.

Supercritical fluid extraction has been widely employed in the extraction of high purity substances. In this study, we used the technology to obtain oil from seeds from a variety of grapes, from vinification residues generated in the Southern region of the state of Rio Grande do Sul, Brazil. This work encompasses three varieties of Vitis vinifera (Moscato Giallo, Merlot, and Cabernet Sauvignon) and two of Vitis labrusca (Bordô e Isabel), harvested in 2005 and 2006. We obtained the highest oil content from Bordô (15.40%) in 2005 and from Merlot (14.66%), 2006. The biggest concentration of palmitic, stearic, and linoleic acids was observed in Bordô, 2005, and in Bordô, Merlot, and Moscato Giallo, 2006. Bordô showed the highest concentration of oleic acid and α-tocopherol in both seasons too. For the equivalent of procyanidins, we did not notice significant difference among the varieties from the 2005 harvest. In 2006, both varieties Isabel and Cabernet Sauvignon showed a value slightly lower than the other varieties. The concentration of total phenolics was higher in Bordô and Cabernet Sauvignon. The presence of these substances is related to several important pharmacological properties and might be an alternative to conventional processes to obtain these bioactives.